Buenos Aires Forms Its Own Government in the May Revolution

In May 1810, a British ship brought newspapers to Buenos Aires confirming that French forces under Napoleon had swept through Andalusia, capturing Seville and dissolving the Supreme Central Junta that governed Spain in the absence of the deposed King Ferdinand VII. In response, remnants of Spanish resistance had gathered at Cadiz to establish a Council of Regency. For the residents of the Viceroyalty of the Rio de la Plata, these reports threw the legal basis of colonial governance into turmoil. Viceroy Baltasar Hidalgo de Cisneros issued a proclamation on 18 May acknowledging the crisis, and local military leaders and criollo intellectuals quickly learned the full scope of the imperial collapse.

Tensions between American-born criollos and European-born peninsulars had been mounting for years over trade restrictions, administrative appointments, and the defense of the colony. When British forces invaded Buenos Aires in 1806 and Montevideo in 1807, the local population repelled the attacks largely through criollo volunteer militias, including the prominent Patricios Regiment under Cornelio Saavedra, while imperial authorities offered no military assistance from Europe. The successful defense raised the prestige of the local regiments. Concurrently, the royal family's abdication in Europe fueled widespread convictions that imperial administration lacked legitimacy.